If Thunderbird was configured to use STARTTLS for an IMAP connection, and an attacker injected IMAP server responses prior to the completion of the STARTTLS handshake, then Thunderbird didn't ignore the injected data. This could have resulted in Thunderbird showing incorrect information, for example the attacker could have tricked Thunderbird to show folders that didn't exist on the IMAP server. This vulnerability affects Thunderbird < 78.12.
A file with a long filename could have had its filename truncated to remove the valid extension, leaving a malicious extension in its place. This could potentially led to user confusion and the execution of malicious code.<br/>*Note*: This issue was originally included in the advisories for Thunderbird 102.6, but a patch (specific to Thunderbird) was omitted, resulting in it actually being fixed in Thunderbird 102.6.1. This vulnerability affects Firefox < 108, Thunderbird < 102.6.1, Thunderbird
security update
A mechanism to spoof the addressbar through the user interaction on the addressbar and the "onblur" event. The event could be used by script to affect text display to make the loaded site appear to be different from the one actually loaded within the addressbar. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 52.1, and Firefox < 53.